Some vehicles include brake systems that operate based on pressure differentials in fluid disposed in the brake systems. For example, air brakes in some vehicles (e.g., rail vehicles) may disengage when the air pressure in the air brakes is decreased. The air brakes in such vehicles may be released in certain environments in order to perform operations on the vehicles. The air brakes in rail vehicles, for example, may be disengaged while in a rail yard in order to more freely roll the rail vehicles around within the rail yard.
In order to disengage the air brakes of vehicles, a human operator may pull on a lever that opens a valve of the air brakes. The valve is opened and the air within the brake system is bled (e.g., the air flows out of the brake system) to reduce the pressure within the brake system and disengage the air brakes. Use of human operators in a rail yard, however, includes many problems. The operations taking place in a rail yard pose safety risks to the human operators. Additionally, the use of human operators can involve increased cost relative to automated systems.
But, automated systems pose problems as well. Although applicant is unaware of any automated system that can bleed air brakes of a vehicle, a critical step is for the automated system to grasp the brake lever. To grasp the brake lever, the automated system relies on an estimation of the brake lever position and a position/velocity control of an end-effector to grasp the brake lever. However, imprecise or inaccurate estimations of the brake lever position, for example, due to noises in the measurement, error in the recognition and segmentation of the brake lever, and/or the like, may have the end-effector have an improper grasp of the brake lever. The improper grasp may result in damaging the automated system such as the end-effector and/or prohibit the automated system from grasping the brake lever. Thus, there is a need to have an automated system with a force and/or torque control loop to enable the automated system to grasp the lever firmly with imprecise or inaccurate estimations.